This study investigated the gain of the human telomerase RNA gene TERC at 3q26 in patients with uterine cervix disease in the southern part of China and assessed the relationship between TERC gain and cervical pathological findings. One hundred ten cervical specimens, which were collected from patients with various kinds of uterine cervix disease that was subsequently diagnosed as chronic cervicitis and with examination results negative for intraepithelial lesion or malignancy (NILM, n = 23), mild dysplasia (cervical intraepithelial neoplasia type 1 [CIN1], n = 37), moderate dysplasia (CIN2, n = 12), severe dysplasia (CIN3, n = 10), and squamous cell carcinoma (SCA, n = 28) confirmed by histologic diagnosis, were analyzed for the proportion of abnormal cells with TERC gain using a commercially available 2-color fluorescence in situ hybridization (FISH) probe. The cases with a higher proportion of abnormal cells than the threshold evaluated by NILM were recorded as positive TERC gain. The chi and Kruskal-Wallis tests were used to assess the associations between FISH findings and diagnoses. The incidence of positive TERC gain in the cases diagnosed as NILM or CIN1 was significantly lower than that in cases diagnosed as CIN2, CIN3, or SCA (P < 0.01). In addition, a significantly higher proportion of abnormal cells with TERC gain was found as a pathological change from CIN1 to SCA (P < 0.01). We conclude that the TERC gain seems to be an important associated genetic event in CIN and carcinoma; FISH is a potential tool for the diagnoses of uterine cervix disease.